Selector control switch



.. De@ 15, l936- E. J. w. RAGSDAL'E 2,064,179

SELECTOR CONTROL SWITCH Fil-ed Aug. 20, 1934 flr" in WwW/ y INVENTOR. EAQL 1W. QAGSDALB.

ATTORNEY.

Patented Dec. 15, 1936 l'iED STATES PATENT orgie Edward G. Budd Manufacturing Company,

Philadelphia, Pa., a corporation of Pennsyl- Vania Application August 20, 1934, Serial No. 740,594

5 Claims.

This invention relates to electric control devices and more particularly to a fluid operated switch arranged for selective actuation by and/ or independent of a fluid pressure medium.

In electric welding operations where portable welding tools and guns are utilized, it is desirable to frequently test the welding equipment ior purposes of ascertaining whether the electric control is operating, Whether the fluid pressure control is operating and where both are cooperatively arranged, whether both are operating and also to have a means whereby any one or all of such operations may be checked independently or collectively.

I have attained the foregoing desired objects, among others not specically enumerated, by constructing a fluid operated switch having a variable Selector control.

My invention will be better understood from the following description and appended claims when considered in connection with the accompanying drawing wherein like ordinates represent corresponding parts on the various iigures:

Figure 1 shows the switch oi my invention applied to a welding gun.

Figure 2 shows an axial cross section through the switch in operated position.

Figure 3 shows a similar view to Figure 2, wherein the selector control has been operated.

Figure 4 has a similar partial cross section showing the switch in selectively inactive position.

Figure 5 shows a section on line 5--5 of Figure 2.

Figure 6 shows a transverse axial cross section on line 6-6 of Figure 2.

` in its at present most useful field of use namely applied to the portable welding gun.

This is clearly illustrated in Figure l wherein is shown a portable welding gun le having a relatively fixed electrode Il and a movable electrode I2, the latter arranged to be moved by piston I3 housed within the cylinder it, which cylinder is in turn attached to a hand grip I5.

Fluid control, for example by pneumatic pressure, is attained from the air line I6 and the control valve il, which valve is operated from a lever I3 in the hand grip, the air communieating with the cylinder le by means of the passage l9 and the valve l1 being so arranged that upon release of air pressure in the gun, the cylinder exhausts through the port 2i) to the atmosphere. To avoid building up of undesirable pressure on the opposite side of the piston, a small relief valve or port 2l is provided in the cylinder casing. Secured to the cylinder wall i4 is the selector switch 22 connected to a small port 23 by screw threaded engagement.

The normal operation of the apparatus occurs in the following manner:

The welding gun l0 is positioned with respect to the work so that complemental iiange portions or other parts to be welded are positioned between the electrode or die members Il and l2. The lever i8 is actuated and air pressure is applied, moving the piston from left to right thus creating a rm grip upon the work parts.

Upon cessation of movement of piston I3 and electrode i2 the pressure within the cylinder and switch begins to build up and at the point of predetermined pressure the switch 22 is actuated creating a continuous circuit from conductor 24 to conductor 25, and thence to the apparatus which controls or effects the energization of the primary circuit of a welding transformer. If it is desired to test the pneumatic operation of the .A

gun without sending an impulse of welding energy to the electrodes, the selector control member 25 is operated so that the electrode can be moved relatively without effecting any circuit connection between conductors 24 and 25 as in Fig. 4.

If it should be desired to test the electrical application without applying pneumatic pressure, the circuit between conductors 213 and 25 may be accomplished by operation of element 23, as in Fig. 3. t

The more detailed description of these features, as well as the special embodiment 0f the invention shown, follows: The switch, in what is believed to be one simple embodiment, is shown clearly in Figure 2 and comprises the following parts: An outer substantially cylindrical member 36, preferably being of insulating material, to which at one end is secured in screwthreaded engagement as at 3l, a metallic member 32. IThis member is internally threaded for engagement with the tubular wall 30 and externally threaded at 23 for engagement with a welding gun or other apparatus to which it may be attached. Passing centrally from this member to the small passageway 33 which transmits the air or othei` uid pressure from the interior of the cylinder 2l to the interior 34 of the switch and substantially centrally of the tubular outer wall 3l) is a concentric insulating member 35 which serves both as a bearing for the fluid actu- .ated switch element and as a supporting and retaining structure for the electric contacts which provide interiorly of the switch continuations of theconductors 24 and 25.

'Ihe far end ofthe tubular member 30 is closed by a metal cap` 36 which isfrmly' secured to the tube 30 by screws 31, or, by Yway of variation, it may be in screw threaded engagement therewith if this latter method of securement should which grooves are preferably diametricallyoppobe desirable.

The electrical conductors 24 and 25 extend internally of the switch housing and are secured therein by suitable screws 38 and 35 respectively.y

The circuit path is continued by means of two flexible conducting strips 40 and 4|. These metal members extend internally of the cylinder and are secured therein by proper grooves 42 and 143 retained in itsV inactive position, namely in the position shown on Figure 3, by means of a helical spring 5|. Upon admission of pressure through passageway 33, the piston 46 is forced to the right against spring 5I to the position shown in Figure 2 wherein an electric circuit is completed from conductor 24 to connection 38', contact 40, Vcontact tip 44, contact 4|, connection 39 :to conductor 25. Upon release Vof. pressure, the spring again forces piston to left and breaks the circuit.

At-the opposite end of the switch is a selector control 26, of insulating material comprising a disc-like central portion 53,`an elongated operating portion 52 and an elongated portion 54 at the opposite sideof the central portion from the first named operating portion and a conducting ring 55.` This member isretained in the position of Figure 2 by means of a spring 55. The selector 90 degrees from the position shown in Figure 2 to the position shown in Figures 3 and 4. Under these circumstances portion 54 separates the contacts 4|] and 4| due to its turning from the full line position of Figure 7 to the dotted position. Thepiston may move to the right, but the coriducting cap 44 does'not vengage Vvthe contacts 40 and 4|. Y

After the equipment has been tested, the weld can be made in either of the following ways:

(1) Byturning the selector control'uback to its original position as in Figures 2 and allowing the contacts to engage con-ducting cap, jor- V(2) while retaining the selector element in the position of Figures 3 and 4, it may be pushed inwardly against the opposition of spring 56 and close circuit as seen in Figure 3 from the contact 40 to they conducting ring 55`and thence to the contact 4|. VIn this-manner, I have accomplished' great selectivity of control, easy testing of the istics independently as well as collectively.V

While, by way of illustration and example I` have described my invention in connection with apreferred Vembodiment thereof as to structure, andthe preferred manner of practicing it, it will be obvious to those skilled in the art, after understanding the foregoing specification, that various changes and modifications may be made withoutv departing from the spirit or scope of the invention and Iaim in the appended claims to cover all Asuch modiiications and changes.

What I claim is:

1. A selector switch comprising a plurality of contacts providing an open circuit arrangement, a contact arrangedto bridgesaid first named contacts, fluid pressure means arranged to effect the bridging engagement of said contact, selector control means arranged to render said pressure operated contact means ineiiectiveand contact means controlled by said selector means operable, Vwhile said selector means isV operative to maintain the pressure operated contactrmeans ineffective, to effect closingland opening of a conducting circuit path between said iirst named contact independently of said pressure operated contact. Y Y V 2. A selectorl switch comprising a housing, two contacts within said housing, means providing a conducting circuit path between said contacts and the exterior of said housing, a pressure operated piston within said housing, a contact carried by said piston and arranged upon actuation of said piston'to bridge said first Vnamed contacts, meansarranged to yieldingly maintain said piston carried contact Vout of engagement with said'rst named contacts, a selector element in said housing, a bridging contact carried by'said selector element, yieldable means main-` taining said bridging contact out o-f engagement with said rst named contacts, s aidselector ele- V:ment carrying a projectionV arranged to lie between said iirst named contacts and maintain said viirst named contacts out of contacting engagement with each other.` Y I 3. A selector switch comprising a housing, two contacts within said housing, means providing a conducting circuit path between saidcontacts and the exterior ofsaid housing, a pressure operated piston within said housing, a contact carried by said piston and arranged upon actuation of said piston to bridge said first named contacts, means arranged to yieldingly maintain said piston carried contact out of engagement with said rst named contacts, a selector element insaid housing, a bridging Vcontact carried by said selector element, yieldable means maintaining said bridging contact out of engagement with said first named contacts, said selector elementlcarrying a projection arrangedto lie between said iirst named contacts and maintain Vsaid rst named contacts out of contacting engagement with each other, said selector element arranged upon selective'actuation to render said pressure Y operated contacts ineifective.

4. A selector switchcomprising a housing, two

Vcontactswithin said housing, means providing a V70 ated vpiston within said housing, a contact carl conducting circuit pa'th'between said contacts and the exterior of said housing, apressure operried by said piston and arranged Vupon actuation of said piston to bridge said iirst named con-H tacts', means arranged to yieldingly `maintainV said piston carried contact out of engagement with said iirst named contacts, a selector element in said housing, a bridging contact carried by said selector element, yieldable means maintaining said bridging contact out of engagement with said first named contacts, said selector element carrying a projection arranged to lie between said rst named contacts and maintain said rst named contacts out of contacting engagement with each other, all of the elements of said selector Vswitch being concentric with the axis of the housing.

5. A selector switch comprising a housing, two contacts within said housing, means providing a conducting circuit path between said contacts and the exterior of said housing, a pressure operated piston within said housing, a contact carried by said piston and arranged upon actuation of said piston to bridge said rst named contacts, means arranged to yieldingly maintain said piston carried contact out of engagement with said i'lrst named contacts, a selector element in said housing, a bridging contact carried by said selector element, yicldable means maintaining said bridging contact out of engagement with said first named contacts, said selector element carrying a projection arranged to lie between said rst named contacts and maintain. said rst named contacts out of contacting engagement with each other, said pressure contact and selector element contact arranged to effect circuit closure of the rst named contact due to motion in opposite directions.

EARL J. W. RAGSDALE. 

